Bird Observer VOLUME 28, NUMBERS JUNE 2000 ^ B ir d Observer A bimonthly journal — to enhance understanding, observation, and enjoyment of birds VOL. 28, NO. 3 JUNE 2000 Board of Directors Managing Editor Brooke Stevens Dorothy R. Arvidson Production Editor David M. Larson Susan L. Carlson Alden G. Clayton Department Heads William E. Davis, Jr. Cover Art William E. Davis, Jr. Glenn d'Entremont Where to Go Birding Jim Berry H. Christian Floyd Feature Articles Marta Hersek Janet L. Heywood Book Reviews Alden G. Clayton Harriet E. Hoffman Bird Sightings Robert H. Stymeist David M. Larson Marjorie W. Rines Carolyn B. Marsh At a Glance Wayne R. Petersen Wayne R. Petersen Robert H. Stymeist Managers Associate Staff Subscriptions Carolyn B. Marsh Theodore Atkinson Advertisements Robert H. Stymeist Seth Kellogg David E. Lange Corporate Officers Rene Laubach President Marjorie W. Rines Barbara Lawless Treasurer Sandon C. Shepard Matthew L. Pelikan Clerk Patricia A. O'Neill Simon Perkins Assistant Clerk John A. Shetterly Pamela A. Perry Fay Vale SUBSCRIPTIONS: $21 for 6 issues, $40 for two years in the U.S. Add $2.50 per year for Canada and foreign. Single copies $4.00 (see http://massbird.org/birdobserver/subform.htm) CHANGES OF ADDRESS and subscription inquiries should be sent to: Bird Observer Subscriptions, P.O. Box 236, Arlington, MA 02476-0003 ADVERTISING: full page, $100; half page, $55; quarter page, $35. Send camera-ready copy to Bird Observer Advertising, P.O. Box 236, Arlington, MA 02476-0003. MATERIAL FOR PUBLICATION: BIRD OBSERVER welcomes submissions of original articles, photographs, art work, field notes, and field studies. Please send submissions to the Managing Editor: Brooke Stevens, P.O. Box 236, Arlington, MA 02476-0003, E-mail: [email protected]. If possible, please include a computer disk (Microsoft Word, txt or rtf formats), or e-mail to the editor as an attached file. Include author's or artist's name, address, and telephone number and information from which a brief biography can be prepared. POSTMASTER: Send address changes to BIRD OBSERVER, P.O. Box 236, Arlington, MA 02476-0003. PERIODICALS CLASS POSTAGE PAID AT BOSTON, MA. BIRD OBSERVER (USPS 369-850) is published bimonthly, COPYRIGHT © 2000 by Bird Observer o f Eastern Massachusetts, Inc., 462 Trapelo Road, Belmont, MA 02478, a nonprofit, tax-exempt corporation under section 501 (c)(3) of the Internal Revenue Code. Gifts to Bird Observer will be greatly appreciated and are tax deductible. ISSN: 0893-4630 CONTENTS Status of Common Loons on Squam Lake in 1999 Amy Wright and Kate Taylor 148 W inter Population Trends of Six Species of Sparrows Thomas R. Hamilton 154 The Change in the Numbers of W intering Hooded M ergansers (LOPHODYTES CUCULLA TUS) in N ew England Steve Davis 164 Birding the M yles Standish State Forest in Plymouth Glenn d ’Entremont 171 Birds and Building a Backyard Pond Alan E. Strauss 111 Young Birders Big Day Birding: A Change of Pace Barrett Lawson 180 Pocket Places Steele Farm, Boxborough Judy Bartos 183 Hot Birds 184 Yard Birds 185 Field Notes An Eastern Bluebird Nest with a Twist Dan Furbish 189 Playing Tag with Osprey Tod McLeish 192 Osprey in Revere Geoffrey Wood 194 About Books: Looking Back Paul M. Roberts 195 Bird Sightings: Jan./Feb. 2000 Summary 199 A bout The Cover: Piping Plover William E. Davis, Jr. 215 About the Cover Artist: Rob Gough 216 At a Glance Wayne R. Petersen 217 Cover Illustration: Piping Plover by Rob Gough Note from the President: From time to time birders tell us about local spots that have brought them pleasure. These places may not merit entire articles, but are worth sharing with other birders who may live nearby or be visiting the area. We invite you to contribute to our new, occasional series and share your "Pocket Place ” with our readers (see page 183). M. W.R. BIRD OBSERVER Vol. 28, No. 3, 2000 147 Status of Common Loons on Squam Lake in 1999 Amy Wright and Kate Taylor Introduction By 1975 the Common Loon (Gavia immer) population in the state of New Hampshire was in notable decline. Inl976 the Loon Preservation Committee (LPC) was created to address concerns about the impact of human activities on loons. Over the next several years the LPC was able to document a decrease in the presence and productivity of loons in New Hampshire, resulting in the registration of the Common Loon as a state-listed threatened species in 1979. Today, the LPC continues to study the breeding success of loons in the state. A self-funded project of the Audubon Society of New Hampshire, LPC’s mission is the restoration and maintenance of a healthy loon population, with the ultimate goal of reviving the role of New Hampshire’s loons in the regional ecosystem. The LPC aimually conducts a statewide survey of loons. The survey grew from the efforts of Squam Lake residents to organize a loon census of Squam Lake (which includes Little Squam Lake), which is centrally located in Grafton County, New Hampshire. Squam Lake is unique among lakes in the statewide survey both historically and biologically. Squam Lake is considered a fairly well-developed lake that has heavy recreational use, yet it hosts one of the highest concentrations of breeding loons in the state. Prior to 1970, loons were considered nuisance birds that impacted local fishing, and game wardens were instructed to shoot the birds on sight (R. Wood, pers. comm.). The filming of the movie “On Golden Pond” at Squam Lake in 1981 helped to elevate the status of loons, and today loons help to define the Squam lakes region. Tourists attracted to the area have become very important to the region’s economy. Although LPC’s mission has grown to encompass loon-monitoring statewide, data on the Squam Lake population represent the most complete subset of LPC’s data archive. These birds are, however, the most intensively managed of any New Hampshire loons. Armual management techniques include providing alternative nest sites and restricting traffic. The LPC is also developing long-term interactive educational programs with the Squam lakes’ residents. Squam Lake requires a full-time LPC field biologist for surveying, in addition to residents who aid in protecting loon families facing increasing human disturbance. Squam’s long-term data set, and the intensive monitoring system, provides a unique measure of changes in environmental quality, and an important foundation for studies of loon mortality and the impact of contaminants over time. Here we report the results of the 1999 field season at Squam Lake. Study Area Glacially formed 40,000 years ago, Squam Lake is the third largest lake in New Hampshire, totaling 6,770 acres. Debris carried by glacial melt water rivers formed 148 BIRD OBSERVER Vol. 28, No. 3, 2000 Squam’s peninsula and islands (Noon 1990). The many islands and secluded coves of this lake provide habitat for a variety of birds, including Common Mergansers, Black Ducks, warblers, vireos, Killdeer, Barred Owls, kingfishers, hummingbirds, and Great Blue Herons (Ridgeley 1988). Recently, Bald Eagles have also been reported (C. Martin pers. comm.). Mammals such as mink, otter, and raccoon are quite common along the shoreline. It is thought that loons first appeared on Squam nearly 10,000 years ago (Noon 1990). Today, it hosts a population of 50-60 loons, with 16 territories established during the breeding season (Figure 1). Figure 1. A Map and Chart of 1999 Territories Rafts Nesting Chicks Chicks Code Name o f Territory floated Pairs Hatched Surviving in August A Little Squam - X 0 _ B Piper Cove XX 1 1 C Perch Island - X 1 1 D Great Island X -- E Heron Cove X (2) X 1 - F Moon/Bowman X 1 - G Kimball Island X -- - H Sturtevant Bay XX 1 1 1 Moultenboro Bay - X 1 1 J Yard islands - - _ - K Long Point X --- L Squaw Cove - X 0 - M Rattlesnake Cove - X 0 - N Five Finger Point XX 0 - 0 Long Island - -- - P Mink Island X X 1 1 BIRD OBSERVER Vol. 28, No. 3, 2000 149 Methods In May 1999 a field biologist was hired to determine the abundance, distribution, and reproductive success of loons of Squam Lake. Data were collected on territorial pairs (defined as a pair of loons defending a territory for at least 4 weeks) and single birds (adults that had not established a pair bond lasting 4 weeks). Nest sites were mapped on 1:24,000 USGS topographical maps, and hatch dates were calculated by counting 29 days from the onset of incubation. Information gathered on successful nests included number of chicks, number of unhatched eggs, and chick survival. Field biologists also collected data on return chronology, adult return rates, mate fidelity, and territory faithfulness for banded birds, and speculated on the cause of failed nests (Taylor and Vogel 1997). At the first sign of nesting, or with the establishment of a brood site, protective signs and float lines were placed in areas of high visibility to restrict boats from the area. When field biologists were present, they restricted boat traffic in sensitive areas under the authority of the New Hampshire Marine Patrol. Nesting platforms (“rafts”), which provide artificial nest sites, were constmcted by volunteers or by field biologists according to specifications provided by LPC (Figure 2). Rafts were deployed at sites where established pairs had experienced successive nest failures due to artificial water level fluctuations or shoreline predation (LPC, 1985, 1990, 1997). Rafts do not serve to attract loons to water bodies with unsuitable territories (McIntyre 1975). Figure 2. A Diagram of Loon Nesting Raft Configuration Abandoned loon eggs were collected as part of the survey.